Anastomosis device and method

ABSTRACT

An anastomosis device for use in coupling an end of a graft vessel to a side of a target vessel. The target vessel has an opening formed in a side wall thereof for insertion of the device. The device comprises a tubular member, at least a portion thereof being radially compressible to a compressed state for insertion of the tubular member into the opening in the target vessel and expandable from the compressed state to an expanded state for engagement of an inner graft vessel surface with an inner surface of the target vessel after insertion of the tubular member into the opening in the side wall of the target vessel. The compressible portion of the tubular member has an inner surface and an outer surface defining a wall thickness therebetween. The wall thickness of the compressible portion in its compressed state is less than the wall thickness of the compressible portion in its expanded state.

This application is a continuation of Ser. No. 09/037,109 filed on Mar.9, 1998, now U.S. Pat. No. 6,176,864.

FIELD OF THE INVENTION

The present invention relates generally to medical devices and methodsfor performing a vascular anastomosis and, more particularly, topreferred devices and methods for sealingly joining a graft vessel, suchas a coronary bypass graft, to the side wall of a target vessel, such asa coronary artery, in an anastomosis.

BACKGROUND OF THE INVENTION

A manifestation of coronary artery disease is the build-up of plaque onthe inner walls of the coronary arteries, which causes narrowing orcomplete closure of these arteries, resulting in insufficient bloodflow. This deprives the heart muscle of oxygen and nutrients, leading toischemia, possible myocardial infarction, and even death. Surgery toalleviate this problem often involves creating an anastomosis between acoronary artery and a graft vessel to restore a blood flow path toessential tissues. An anastomosis is a surgical procedure by which twovascular structures, such as a graft vessel and a coronary artery, areinterconnected.

Current methods available for creating an anastomosis include handsuturing the vessels together. Connection of interrupted vessels withstitches has inherent drawbacks. For example, it is difficult to performand requires great skill and experience on the part of the surgeon duein large part to the extremely small scale of the vessels. For example,the coronary arteries typically have a diameter in the range of betweenabout 1 to 5 mm, and the graft vessels have a diameter on the order ofabout 1 to 4 mm for an arterial graft such as a mammary artery, or about4 to 8 mm for a vein graft such as a saphenous vein. Other drawbacks ofconnection with stitches are the long duration of the operation, duringwhich period in conventional open-heart coronary artery bypass graft(CABG) surgery the heart is arrested and the patient is maintained undercardioplegic arrest and cardiopulmonary bypass. Cardiopulmonary bypasshas been shown to be the cause of many of the complications that havebeen reported in conventional CABG, such as stroke. The period ofcardiopulmonary bypass should be minimized, if not avoided altogether,to reduce patient morbidity.

One approach to coronary artery bypass grafting that avoidscardiopulmonary bypass is performing the suturing procedure on a beatingheart. At present, however, safe, reproducible, and precise anastomosisbetween a stenotic coronary artery and a bypass graft vessel presentsnumerous obstacles including continuous cardiac translational motionwhich makes meticulous microsurgical placement of graft suturesextremely difficult. The constant translational motion of the heart andbleeding from the opening in the coronary artery hinder precise sutureplacement in the often tiny coronary vessel.

The above mentioned drawbacks of hand suturing have led to thedevelopment of various approaches to stitchless vascular connection oranastomosis which has the advantage of quick and simple execution andundamaged vascular endothelium. Some approaches to stitchlessanastomosis used rigid rings prepared from various materials. Forexample, Geotz et al., INTERNAL MAMMARY-CORONARY ARTERY ANASTOMOSIS—ANonsuture Method Employing Tantalum Rings, J. Thoracic and Cardiovasc.Surg. Vol. 41 No. 3, 1961, pp. 378–386, discloses a method for joiningblood vessels together using polished siliconized tantalum rings whichare circumferentially grooved. The free end of the internal mammary ispassed through a ring chosen according to the size of the stenoticcoronary artery. The free end of the mammary artery is everted over oneend of the ring as a cuff and fixed with a silk ligature which is tiedaround the most proximal of the circular grooves in the ring. The cuffedinternal mammary artery is inserted into an incision in the targetcoronary artery. The ring is fixed in place and sealingly joined to thetarget coronary artery by tying one or more sutures circumferentiallyaround the target vessel and into one or more circular grooves in thering. An intimal-to-intimal anastomosis results and dissection of bloodbetween the coronary artery and the cuffed internal mammary artery islargely prevented.

The use of metallic coupling rings is also disclosed in Carter et al.,Direct Nonsuture Coronary Artery Anastomosis in the Dog, Annals ofSurgery, Volume 148, No. 2, 1958, pp. 212–218 (describing use of rigidpolyethylene rings for stitchless vascular connections). Moreover, forexample, U.S. Pat. No. 4,624,257 to Berggren et al. describes a deviceconsisting of a pair of rigid rings each having a central openingthrough which the end of the coronary or graft vessel is drawn andeverted over the rings. A set of sharp pins extends outwardly from theface of each ring and pierce through the vessel wall in the evertedconfiguration. The rings are then joined together to align the end ofthe graft vessel with the opening in the target vessel.

However, no permanently satisfactory results have been reported with theuse of rigid rings. A rigid ring presents a foreign body of relativelyheavy weight which does not heal well and produces pressure necrosis.Moreover, the use of rigid rings that completely encircle the graftvessel and the arteriotomy creates a severe “compliance mismatch”relative to both the coronary artery and the graft vessel at theanastomosis site which could lead to thrombosis. That is, recent studiessuggest that the anastomosis site should not be dramatically differentin compliance relative to either the coronary artery or the vasculargraft, which is the case when using rigid rings to sealingly join twovessels together.

Another method currently available for stitchless anastomosis involvesthe use of stapling devices. These instruments are not easily adaptablefor use in vascular anastomosis. It is often difficult to manipulatethese devices through the vessels without inadvertently piercing a sidewall of the vessel. Moreover, as noted above, the scale of the vesselsis extremely small, and it is extremely difficult to construct astapling device that can work reliably on such a small scale to providea consistent and precise leak-free vascular anastomosis.

SUMMARY OF THE INVENTION

The present invention involves improvements to devices and methods forperforming vascular anastomoses. The invention facilitates positioningone vessel in the fluid path of another vessel to enhance the fluid flowjuncture therebetween. In one aspect of the invention, a graft vessel,such as an internal mammary artery, is sealingly joined to a targetvessel, such as a left anterior descending artery. The present inventioneliminates the need for meticulous suturing and may reduce the amount oftime required to make an anastomosis, while still providing asubstantially safe, leak-free anastomosis.

In one aspect of the present invention, an anastomosis device generallycomprises a tubular member. At least a portion of the tubular member isradially compressible to a compressed state for insertion of the tubularmember into an opening formed in a target vessel and expandable from thecompressed state to an expanded state for engagement of the graft vesselwith an inner surface of the target vessel after insertion of thetubular member into the opening in the side wall of the target vessel.The compressible portion of the tubular member has an inner surface andan outer surface defining a wall thickness therebetween. The wallthickness of the compressible portion in its compressed state is lessthan the wall thickness of the compressible portion in its expandedstate.

A method of the present invention generally comprises the steps ofproviding a graft vessel with a fastener coupled thereto, the fastenercomprising a radially compressible portion; exerting an inwardlydirected radial force over at least a portion of the compressibleportion until the compressible portion has an outer diameter smallerthan the diameter of an opening formed in a side wall of the targetvessel; inserting at least a portion of the fastener into the opening inthe side wall of the target vessel; and removing the radial force toallow the compressible portion of the fastener to radially expand tosealingly engage the graft vessel with an inner wall of the targetvessel.

The above is a brief description of some deficiencies in the prior artand advantages of the present invention. Other features, advantages, andembodiments of the invention will be apparent to those skilled in theart from the following description, accompanying drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an anastomosis device of the presentinvention showing a graft coupling member coupled to an end of a tubularmember.

FIG. 1A is a cross-sectional view of the anastomosis device of FIG. 1taken through the line A—A of FIG. 1.

FIG. 2 shows the anastomosis device of FIG. 1 prior to insertion of thedevice into an opening in an introducer.

FIG. 2A shows the anastomosis device of FIG. 1 prior to insertion of thedevice into an opening in an alternative embodiment of the introducer ofFIG. 2.

FIG. 3 is an elevated view of the anastomosis device of FIG. 2 with afree end of a graft vessel inserted therein.

FIG. 4 is an elevated view of the anastomosis device of FIG. 3 with thedevice inserted into the introducer showing the graft coupling member ina compressed state within the introducer.

FIG. 5 is an elevated view of the anastomosis device of FIG. 4 with thefree end of the graft vessel shown extending longitudinally from an endof the introducer.

FIG. 6 is an elevated view of the anastomosis device of FIG. 5 with thefree end of the graft vessel everted over an end of the introducer.

FIG. 7 is an elevated view of the anastomosis device of FIG. 6 showing aportion of the graft coupling member extending longitudinally from anend of the introducer and showing the application of one or more suturesbetween the everted graft vessel and the graft coupling member.

FIG. 7A is an elevated view of the anastomosis device of FIG. 1 showninserted into the introducer of FIG. 2A.

FIG. 8 is an elevated view of the anastomosis device of FIG. 7 insertedinto a target vessel through an incision in the target vessel.

FIG. 9 is an elevated view of the anastomosis device of FIG. 8 after theintroducer has been removed from the fastener showing the completedanastomosis.

FIG. 10 is an alternative embodiment of the anastomosis device of FIG.1.

FIG. 11 shows the anastomosis device of FIG. 10 with a graft vesselinserted therein prior to insertion of the device into an opening in thetubular introducer.

FIG. 12 is an elevated view of the anastomosis device of FIG. 11 withthe device inserted into the introducer and showing the tubular memberin a compressed state within the introducer.

FIG. 13 is an elevated view of the anastomosis device of FIG. 12 withthe free end of the graft vessel everted over an end of the introducer.

FIG. 14 is an elevated view of the anastomosis device of FIG. 13 showinga portion of the tubular member extending longitudinally from an end ofthe introducer and showing the application of one or more suturesbetween the exerted graft vessel and the tubular member.

FIG. 15 is an elevated view of the anastomosis device of FIG. 14inserted into the target vessel through an incision in the targetvessel.

FIG. 16 is an elevated view of the anastomosis device of FIG. 15 afterthe introducer has been removed from the fastener showing the completedanastomosis.

DESCRIPTION OF THE INVENTION

Referring now to the drawings, and first to FIGS. 1 and 1A, ananastomosis device constructed according to the principles of thepresent invention is shown and generally indicated with referencenumeral 8. The anastomosis device (or fastener) 8 is used to connect agraft vessel 10, such as a thoracic artery, to a target vessel 12, suchas a coronary artery, i.e., the left anterior descending artery. Forexample, the device may be used in an end-to-side distal anastomosis tosealingly join a thoracic artery or a saphenous vein graft to a coronaryartery. The anastomosis device 8 of the present invention may also beused in connecting various other vessels or arteries and may be used toconnect synthetic vascular grafts to an artery.

The fastener 8 preferably comprises an elongated, flexible tubularmember 20 and a radially compressible, elongated graft coupling member30 which is coupled to an external surface of the tubular member 20 atone end of the tubular member 20. The graft coupling member 30 can becoupled to the tubular member 20 with biological glue, other adhesivemeans, thread, or by any other suitable means. Alternatively, the graftcoupling member 30 and the tubular member 20 can also be provided asseparate parts. The graft coupling member 30 will be configured to bestretched over one end of the tubular member 20 and secured proximal tothe end of the tubular member 20 by the force of its own naturalcompressibility or by any of the coupling means described above.

The tubular member 20 comprises two tubular layers 22, 26, and a thinflexible central tube 24 interposed between the two tubular layers. Thetubular layers are preferably formed from a biocompatible, implantableplastic material. The central tube 24 is preferably formed from abiocompatible coil such as medical grade stainless steel or nitinol wireor ribbon, but may also be formed from any other sufficiently rigid,biocompatible material such as a plastic, polyurethane or polycarbonatematerial, or any other suitable material as is well known to a person ofordinary skill in the art. The inner and outer tubular layers 22, 26 arepreferably formed from a material having a low durometer hardness toprovide sufficient flexibility to allow the tubular member to bend at anangle of approximately 30° to 60° along a central longitudinal axis ofthe member. Preferably, the inner and outer layers 22, 26 are made froman implantable, flexible plastic such as silicone, although any othersuitable flexible, implantable biocompatible material as is well knownto persons of ordinary skill in the art may be used. The inner and outerlayers 22, 26 are preferably bonded together (similar to braided shafts)by conventional means and the central tube 24 is locked between twolayers.

The inner plastic tube 22 is generally necessary to prevent the centralcoil 24 from scraping and damaging the graft vessel 10. The central coil24 provides strength to the tubular member 20 to prevent it fromkinking, yet is sufficiently flexible to allow the tubular member 20 tobe inserted into the target vessel 12 through an incision 16 formedtherein. The outer plastic tubular layer 26 allows the graft couplingmember 30 to be more easily fitted over the tubular member 20 andcoupled thereto. The tubular member 20 is preferably between about 4.0and 12.0 mm in length, and more preferably about 5.0 to 8.0 mm, forexample. As shown in FIG. 1, the inner and outer layers 22, 26 andcentral coil 24 preferably extend the full length of the tubular member20. The diameter of the tubular member 20 will vary depending on thesize of the graft vessel into which it is inserted. Preferably, theinner diameter of the inner layer 22 will generally be between about 0.5to 6.0 mm for a coronary anastomosis, for example. The total wallthickness of tubular member 20 will be between about 0.100 mm and 0.600mm, and preferably between about 0.100 mm and 0.400 mm, for example. Itis to be understood, however, that other types of tubular members madefrom other types of biocompatible materials and different size tubularmembers may be used without departing from the scope of the invention.For example, the tubular member 20 may be formed from a one-pieceflexible tube (not shown).

The graft coupling member (compressible portion) 30 comprises a tubeformed from a biocompatible, radially compressible material. By“radially compressible”, it is meant that the graft coupling member 30is generally uniformly radially transformable between a free, normalexpanded state and one or more compressed states in which the graftcoupling member 30 has a smaller diameter than in its normal expandedstate. In a preferred embodiment, the biocompatible material comprises anon-metallic foam material which is radially self-expandable. By“self-expandable”, it is meant that the foam material forming the grafttubular member 30 is biased to its expanded state (i.e., will naturallytend to radially migrate back towards its free, normal expanded statefrom its compressed state). The coupling member 30 has an inner surfaceand an outer surface defining a wall thickness therebetween. The wallthickness of the coupling member in its compressed state is less thanthe wall thickness of the member in its expanded state. The foammaterial may be conventional biocompatible foam such as 100 pores perinch foam material, for example. The foam material is substantiallyradially compressible to allow the graft vessel 10 to be coupled to thefoam and to permit the fastener 8 to move longitudinally within thetarget vessel 12 as will be described in greater detail below. Thediameter of the graft coupling member 30 will vary depending on the sizeof the target vessel 12 into which the fastener 8 is inserted.Preferably, the inner diameter of the graft coupling member 30 will beabout 10 to 30% smaller than the outside diameter of the tubular member20, and the outside diameter of graft coupling member 30 will preferablybe between about 10 to 80% larger than an inside diameter of the targetvessel 12.

FIGS. 2–9 show an exemplary use of the anastomosis device 8 of thepresent invention in an open surgical coronary artery bypass graftprocedure via a median sternotomy. This example is meant to be byillustration only, and in no way is meant to be limiting. The presentinvention can be used in other cardiac surgery procedures such asminimally invasive direct coronary artery bypass grafting (MIDCAB) on abeating heart through a small incision (thoracotomy) (about 6–8 cm) inthe left side of the chest wall, in endoscopic minimally invasivecardiac surgery bypass graft procedures, and in other vascularprocedures to join two vessels together. By way of example, the leftinternal thoracic artery is used as the graft vessel 10. In thisexample, the left anterior descending artery is used as the targetvessel 12 and contains a build-up of plaque or narrowing 13. If leftuntreated, this diseased artery may lead to insufficient blood flow andeventual angina, ischemia, and possibly myocardial infarction.

Conventional coronary bypass graft procedures require that a source ofarterial blood be prepared for subsequent bypass connection to thediseased artery. An arterial graft can be used to provide a source ofblood flow, or a free vessel graft may be used and connected at theproximal end to a source of blood flow. Preferably, the source of bloodflow is any one of a number of existing arteries that are dissected inpreparation for the bypass graft procedure. In many instances, it ispreferred to use either the left or right internal thoracic artery. Inmultiple bypass procedures, it may be necessary to use free graftvessels such as the saphenous vein, gastroepiploic artery in theabdomen, and other arteries harvested from the patient's body as well assynthetic graft materials, such as Dacron or Gortex grafts. If a freegraft vessel is used, the upstream end (proximal) of the dissectedvessel, which is the arterial blood source, will be secured to the aortato provide the desired bypass blood flow, and the downstream end(distal) of the dissected vessel will be connected to the target vesselin a distal anastomosis.

In order to perform an anastomosis with the fastener 8 of the presentinvention, the graft vessel 10 is first coupled to the fastener 8 byinserting a free end of the graft vessel 10 through an opening in thetubular member 20 with a conventional insertion device (not shown) andmoving the graft vessel 10 longitudinally within the tubular member 20until the free end of the graft vessel extends a short distance beyondan end of the tubular member as shown in FIG. 3. The fastener 8 with thegraft coupling member 30 attached thereto is then inserted into anopening in a tubular introducer 40 which has an inner diameter smallerthan an outside diameter of the graft coupling member 30 but larger thanan outside diameter of the flexible tubular member 20 (FIG. 2). Theintroducer 40 preferably includes at least one longitudinal perforation(not shown) to allow for easy removal of the introducer as furtherdescribed below. The inner wall of the introducer 40 will radiallycompress the graft coupling member 30 into its at least one compressedstate. The free end of the graft vessel 10 is then everted over an endof the introducer 40 as shown in FIG. 6. The introducer 40 is thenpulled back to a short distance over the fastener 8 (while holdingtubular member 20) to a position in which at least an end portion of thegraft coupling member 30 is exposed and extends a short distance from anend of the introducer 40 and engages with a portion of the graft vessel10 in the everted configuration (FIG. 7). The natural adhesiveness ofgraft vessel 10 may be sufficient to secure the graft vessel 10 to thegraft coupling member 30. If necessary, one or more sutures 50 may beapplied to the graft vessel 10 and the graft coupling member 30 tosecure the graft vessel 10 to the fastener 8 in the event that thenatural adhesiveness and compressibility of the graft vessel 10 isinsufficient to temporarily secure it to the graft coupling member 30.Alternatively, the graft vessel 10 can be secured to the graft couplingmember 30 with biological glue, other adhesive means, by tying one ormore sutures circumferentially around the graft vessel 10, or by anyother suitable means.

An alternative embodiment of the tubular introducer 40′ is shown inFIGS. 2A and 7A. The introducer includes at least one groove 42 formedin one end of the wall of the introducer. One or more sutures 50 can beinserted through the groove 42 to secure the everted graft vessel 10 tothe graft coupling member 30. It is to be understood that the introducermay have configurations other than those shown herein without departingfrom the scope of the invention.

The introducer (40 or 40′) is then introduced into the target vessel 12through an incision (opening) 16 formed in a side wall of the targetvessel 12 (FIG. 8). The incision 16 can be made with the use of aconventional scalpel or other appropriate cutting instrument.Alternatively, a circular or oval punch may be used to facilitate thearteriotomy. The fastener 8 is preferably positioned in the targetvessel 12 via introducer 40, 40′ such that at least an end portion ofthe graft coupling member 30 extends generally coaxial with the targetvessel 12. With the fastener 8 securely positioned in the target vessel12 via the introducer 40, 40′, the introducer can be pulled back overthe fastener to allow the graft coupling member 30 to radially expandback towards its normal expanded state to sealingly engage the fastenerwith an inner wall of the target vessel to complete the anastomosis. Theintroducer 40, 40′ preferably will be a conventional peel-awayintroducer such as that manufactured by Modified Polymer Components,Inc. of Sunnyvale, Calif., so that it can be easily separated andremoved from the fastener 8 and graft vessel 10.

As shown in FIG. 9, the self-expanding nature of the graft couplingmember 30 permits the graft coupling member 30 to radially expand tosealingly engage the graft vessel 10 with an inner wall of the targetvessel 12 to complete the anastomosis. The engagement of the fastener 8with the graft vessel 10 and inner wall of the target vessel 12 preventssubstantial longitudinal movement of the fastener 8 within the targetvessel. If necessary, one or more sutures can be applied to theanastomosis site to prevent the graft vessel 10 from being pulled outfrom the target vessel 12. The foam material forming the graft couplingmember 30 will apply a gentle circumferentially uniform, radial pressureagainst the inverted graft vessel 10 and the inner wall of the targetvessel 12. An intima-to-intima anastomosis results. The flexibility ofthe foam material and the tubular member 20 permits the fastener device8 to be substantially compliant with the target vessel 12 and the graftvessel 10 to reduce the onset of thrombosis.

If required, cardiac stabilization such as described in co-pendingprovisional patent application Ser. No. 60/055,127, for Compositions,Apparatus and Methods For Facilitating Surgical Procedures, filed Aug.8, 1997 and invented by Francis G. Duhaylongsod, M.D, may be used duringthe procedure. Other pharmacological or mechanical methods may also beused.

In an alternative embodiment of the present invention shown in FIG. 10,wherein like numerals represent like parts, the fastener 60 showntherein comprises a single, elongated tubular member 70 made from aradially compressible and radially self-expandable material, preferablya non-metallic foam material. The foam material is preferablysufficiently radially rigid to maintain its shape within the targetvessel 12 to provide a fluid-tight seal, and should also be sufficientlyflexible to be inserted through an incision 16 in the target vessel 12.The foam material in this embodiment is preferably foam such asmanufactured by W. L. Gore of Arizona, for example. Alternatively, thefoam may be a material having 100 pores per inch as described above. Theouter diameter of the tubular member 70 in its free expanded state ispreferably between about 10 to 80% larger than the inner diameter of thetarget vessel 12 into which it is inserted, and the inner diameter ofthe tubular member 70 in its free expanded state is preferably about 10%to 30% larger than the outer diameter of the graft vessel 10. Thetubular member 70 is preferably between about 4.0 and 12.0 mm in length,and more preferably about 5.0 to 8.0 mm in length, for example.

The graft vessel 10 may be coupled to the tubular member 70 and insertedinto the target vessel 12 in substantially the same way as describedabove for the tubular member/graft coupling member combination of FIGS.1-9. Referring to FIGS. 11-16, the foam tubular member 70 and graftvessel 10 is inserted into an opening in a tubular introducer 40 whichhas an inner diameter which is smaller than an outside diameter of thetubular member 70, as shown in FIG. 11. The inner wall of the introducer40 will radially compress the tubular member 70 into a compressed state.A free end of the graft vessel 10 is then inserted through an opening inthe tubular member 70 and everted over an end of the introducer 40(FIGS. 12 and 13). The introducer 40 can then be pulled back a shortdistance over the tubular member 70 (while holding tubular member 70) toa position in which at least an end portion of the tubular member 70 isexposed and extends a short distance from an end of the introducer 40and engages a portion of the graft vessel 10 in the evertedconfiguration (FIG. 14). One or more sutures 50 may be applied betweenthe graft vessel 10 and the tubular member 70 to secure the graft vessel10 to the tubular member 70. Alternatively, the graft vessel 10 may besecured to the tubular member 70 with biological glue, other adhesivemeans, by tying one or more sutures circumferentially around the graftvessel 10, or by any other suitable means.

Alternatively, the tubular member 70 may be coupled to the graft vessel10 by providing an introducer (not shown) as described above withreference to FIG. 7A having at least one groove in a wall of theintroducer which extends axially from an end of the introducer. One ormore sutures can be provided through the groove to secure the evertedgraft vessel 10 to the tubular member 70. The introducer 40 is thenintroduced into the target vessel 12 through an incision 16 in a wall ofthe target vessel 12 and pulled back over the tubular member 70 (FIG.15). The tubular member 70 will then radially expand back towards itsfree, normally expanded state to sealingly join the graft vessel 10 tothe target vessel 12 in a compliant, patent anastomosis (FIG. 16). Ifnecessary, one or more stay sutures can be applied to the anastomosissite to prevent the graft vessel 10 from pulling out the target vessel12. The introducer 40 can then be peeled away from the tubular member 70and the graft vessel 10 to complete the anastomosis procedure.

While the above is a complete description of the preferred devices andmethods of the invention, various alternatives, substitutions,modifications, and equivalents of the devices and methods described arepossible without departing from the principles thereof. For example, itmay be possible for a surgeon to radially compress the graft couplingmember with his fingers or other appropriate surgical instrument withoutrequiring the use of a separate tubular introducer. The surgeon can thendeftly evert the graft vessel over the compressed graft coupling member(or one-piece tubular member) to couple them to one another. The surgeoncan then use his fingers to continue to radially compress the graftcoupling member as it is inserted into the target vessel through anincision formed therein. By removing his fingers from engagement withthe graft coupling member, the graft coupling member will tend toradially expand back towards its normal expanded state to sealinglyengage the graft vessel with an inner wall of the target vessel in acompleted anastomosis. Similarly, other alternatives, substitutions,modifications and equivalents are possible without departing from thescope of the inventions described herein. Therefore, nothing disclosedabove should be taken to limit the scope of the invention, which isdefined by the appended claims.

All references cited herein are incorporated by reference.

1. An anastomosis device for use in coupling a graft vessel to a side ofa target vessel, the target vessel having an opening formed in a sidewail thereof, the anastomosis device comprising: a graft vessel havingan end portion and a proximal portion; a coupling member attached to thegraft vessel: a flexible tube attached to the coupling member: andwherein the graft vessel extends through the flexible tube, a free endof the graft vessel is evened over and coupled to at least a portion ofthe coupling member, the coupling member is radially compressible to acompressed state for insertion of at least a portion of the couplingmember and at least a portion of the end portion of the graft vesselinto the opening of the target vessel, and the coupling member ispositionable within the opening of the target vessel when the couplingmember expands from the compressed state to an expanded state.
 2. Thedevice of claim 1 wherein said coupling member is self-expanding.
 3. Thedevice of claim 1, wherein said flexible tube is made from animplantable biocompatible material.
 4. The device of claim 3 whereinsaid biocompatible material comprises a plastic material.
 5. The deviceof claim 1, wherein the flexible tube further comprises a coilinterposed between an inner and outer layer.
 6. The device of claim 5wherein said coil is formed from a biocompatible material.
 7. The deviceof claim 6 wherein said biocompatible material is selected from a groupconsisting of stainless steel and nitinol.
 8. The device of claim 6wherein said biocompatible material is selected from a group consistingof plastic, polyurethane, and polycarbonate material.
 9. The device ofclaim 5 wherein said inner and outer layers are formed from a lowdurometer plastic material.
 10. The device of claim 9 wherein saidplastic material is silicone.
 11. The device of claim 1 wherein saidcoupling member is made from a biocompatible material.
 12. The device ofclaim 11 wherein said biocompatible material comprises a non-metallicmaterial.
 13. The device of claim 12 wherein said non-metallic materialcomprises a foam material.
 14. The device of claim 1 wherein an outsidediameter of the coupling member in its expanded state is between about10 to 80 percent larger than an inside diameter of the target vessel.15. The device of claim 1 wherein an inside diameter of the flexibletube is between about 0.5 mm to 6.0 mm.
 16. The device of claim 1,wherein the graft vessel is coupled to the coupling member with one ormore sutures.
 17. The device of claim 1 further comprising an introducerhaving an outer diameter sized to permit insertion of the introducerthrough the opening in the side wall of the target vessel.
 18. Thedevice of claim 17, wherein the introducer has a groove farmed in oneend thereof through which a suture can be attached to the graft vesseland the flexible tube.
 19. The device of claim 18 wherein the introduceris configured to be pulled back and separated from the flexible tubeafter the introducer is inserted at least partially into the targetvessel through the opening in the side wall of the target vessel. 20.The device of claim 1, wherein the graft vessel comprises one of anartery, a vein, and a synthetic graft.
 21. An anastomosis device for usein coupling a graft vessel to a side of a target vessel, the targetvessel having an opening formed in a side wall thereof, the anastomosisdevice comprising: a graft vessel having an end portion and a proximalportion; a coupling member attached to the graft vessel; a flexible tubeat least partially disposed about the graft vessel and attached to thecoupling member; and wherein a free end of the graft vessel is evenedover and coupled to at least a portion of the coupling member, thecoupling member is radially compressible to a compressed state forinsertion of at least a portion of the coupling member and at least aportion of the end portion of the graft vessel into the opening of thetarget vessel, and the coupling member is positionable within theopening of the target vessel when the coupling member expands from thecompressed state to an expanded state.